Tick Data Archive

Tick-level archive — one file per trading session (cut at 21:00 UTC). L1 = every field from the live stream; L1 Compact = 13 core fields from DTN; L2 = top-10 price-level book per change (price, size, order count).
The Databento tapes are reduced NDJSON (session cut at 17:00 ET, each day shipped as a full-session file plus an RTH-only slice): Matched = live, trades interleaved with the top-10 book; Compact = historic DTN pull, trade lines only (IQFeed has no market-depth history).